[Bill-P]

My dad got the M50 coiled cord version a while ago, and I was thoroughly impressed by them, enough that I almost got a regular M50S from another Head-Fi'er, but then a family emergency came up, and just last week, I saw the LE of the M50S, and couldn't resist.
 
So they finally came today, and here are some quick impressions compared to my dad's M50, after a quick listen the last hour to Blue Man Group's How To Be a Megastar! 2008 Blu-Ray on my MacBook Pro with an external BD drive:
 
1) Bass was less "clogged" in the LE vs the regular. It sounded cleaner, though not necessarily tighter. In fact, I think it lacked the impact of the regular. Low bass was equally good on both.
2) Mid was less recessed. Voices were more "in your face" than the regular version. During "Sing Along", the regular version sounded like the singers were further away.
3) High was a bit more detailed, and noticeably less sibilant. It sounded like the graph of an exponential function (the f = 2^x function). Like this:

4) Fiio E7 added into the mix made bass even cleaner, with more punch. The same with the regular version, but the LE was still noticeably cleaner.
5) Soundstage was slightly different. The regular version had more space, while the LE seemed a little bit more constricted. I hope this would be remedied after burn in.
6) The pad was a lot more comfortable than the regular. The clamping force was strong, being that the LE was brand new, just fresh out of the box, but the regular was still a bit more uncomfortable to me even with less clamping force. In fact, I think less clamping force reduced noise isolation in the regular version.
7) Noise isolation seemed better with the LE vs regular, and I think due to there being more clamping force.
8) LE leaked a lot less than regular as well, and I think also due to there being more clamping force.
 
So overall, I think the LE actually has improved sound signature and comfort compared to the regular (coiled cord version) to my ears. Sound stage is the only thing that I found the LE to lack compared to the burned in regular version, but I'm very hopeful that this would be remedied after another 100 hours of listening.
 
Overall, came away even more impressed than the first time I put the regular version on. Definitely worth every penny of it in my opinions.
 
Update 1:
 
I forgot to mention. My dad's M50 is white box. Output was via my MacBook Pro's headphone port, then through Fiio E7 as a DAC and then Fiio E7 as an amp for the MBP's headphone port. E7 as DAC sounded best to me.
 
Update 2:
 
After just 3 hours of listening, the sound stage has now improved drastically. So have details. Now the LE sounds noticeably better than the regular M50 to me... in just about every way except that bass still lacks impact.

 

[GigaFi]

Do you have the first or second version of the M50? (second version has a white box)
 
I thought the LE would be the same as the second so maybe it's a burn in thing...or maybe not.
 

 

[Bill-P]

My dad's M50 is the white box version, so I'd guess second.

 

[Aglets]

Just thinking about getting M-50's as these pop up :/. Now if I could just find these ANYWHERE in Canada at a semi-reasonable price..

 

[Bill-P]

Quote:

Just thinking about getting M-50's as these pop up :/. Now if I could just find these ANYWHERE in Canada at a semi-reasonable price..

Audio Technica actually had someone ask about this on their website a while ago from what I can see, and their response was for the inquirer to call the number 800-567-3275.
 
Here's the original response:
http://answers.audio-technica.com/answers/1213-en_us/product/ca4c1047baadceb9/ath-m50s-le-limited-edition-professional-studio-monitor-headphones-with-straight-cable-questions-answers/questions.htm

 

[Mad Lust Envy]

Heard both side by side today. Same M50 sound. I have pics but have to upload them when I get home. White box vs LE. Both straight cable.

My assumption as to sonic differences for OP was due to the coiled cord. Longer runs alter SQ, and I'm gonna assume the coiled version has a long cord when straightened.

That and clamp. The old M50 was used and no doubt didn't have the same exact clamp as the fresh LE. Clamp CAN slightly alter SQ.

 

[Bill-P]

Quote:

Heard both side by side today. Same M50 sound. I have pics but have to upload them when I get home. White box vs LE.

Really? That's interesting. Both my older brother and I could swear that the LE sounds noticeably better than the regular version. Perhaps that only applies to the coiled cord version of the regular. Either that or I think it might be that my dad's M50 has some inherent fault somewhere...

 

[Mad Lust Envy]

Terribad pics. If I don't use flash, it's a blurry mess.

 

[ViralRazor]

Pretty sure they're the same specification wise (that is audio technica intended them to be the same)
 
But there might be some manafacturing differences as the LE version would be made with a different batch and the housing is obviously different.

 

[rhythmdevils]

Quote:

Heard both side by side today. Same M50 sound. I have pics but have to upload them when I get home. White box vs LE. Both straight cable.
My assumption as to sonic differences for OP was due to the coiled cord. Longer runs alter SQ, and I'm gonna assume the coiled version has a long cord when straightened.
That and clamp. The old M50 was used and no doubt didn't have the same exact clamp as the fresh LE. Clamp CAN slightly alter SQ.

Are you kidding?  I use an extension cable and it does not do anything significant. 

 

[Mad Lust Envy]

It was an assumption, nothing concrete. People here seem to believe in cables, so it was a possible theory.

 

[RPGWiZaRD]

Quote:

It was an assumption, nothing concrete. People here seem to believe in cables, so it was a possible theory.

I believe in cables, why? Because I hear the bloody difference that's why! xD Doesn't need $50+ cables, a cheap cable vs another cheap cable can provide a slightly different sound. My Q40 goes from very tiny bit recessed treble to neutral/tiny bit emphasized treble depending on cable.
 

 

[Mad Lust Envy]

I wasn't for or against cables, I don't have enough evidence to prove or disprove it. I do remember adding an extension cable in the chain quite a few times and making the sound signature warmer. That's about it. So my theory is that the longer run on the coiled cable may alter the sound slightly vs the straight cable.

 

[Bill-P]

Here are some photos I took with my iPhone today. I don't think the coiled cord version has longer cable since the straight cord's cable is almost 3 times the length.
 

 
Close up

 
They aren't really that different.

 
And here's the test rig: MacBook Pro 15" 2011 with Fiio E7 as DAC and both headphones connected at once. I tried switching the plug, but there was no difference in sound quality.

 
It's the 2nd day, and my assessment is still the same as yesterday. 50th Anniversary Edition M50S sounds noticeably clearer, cleaner, and less sibilant, while the regular coiled cord M50 has more bass thump, but bass is bloated and less clear.
 
Edit: and I forgot to mention. Today I'm testing out some music from my iTunes library instead of movies. Most of my iTunes library (about 99%) is 320kbps MP3. Currently testing Nalepa's Monday (The Glitch Mob Remix) from Flatlands Remixes.

 

[Mad Lust Envy]

Bill, can you try and uncoil it for comparison? They probably do have similar lengths.